This is a screen shot from when we were in Europe. It’s the weather app Windy in radar mode. I was astonished when I first saw this.
If you happened to not have hung on every word of my 11 post series, Bad Weather, here’s the skinny as this country mouse understands it (as radar pertains to weather). Radio waves are emitted by a transmitting antenna (as part of the transmitter). The radio waves are either reflected by something (rain, snow, fog, etc.) and are transmitted back to the receiving antenna (receiver, almost always part of the same contraption as the transmitter, i.e., a transceiver ), or they are not (as is the case when there’s nothing for the waves to “bounce off of”). If they are, processing the information will yield information about the distances, velocity, angle, type of precipitation, etc.
Radar images can be either smoothed or raw. In the image above, they are smoothed. That is, information from multiple transceivers attending to the same space will be averaged. (That’s not really how it works but it’s a useful way to think about it.)
Raw images are the ones your local Weather Dude shows you when he zooms into the intersection of Main & 2nd St.
For a big picture of what’s happening, you want to look at a smoothed image, as above.
Here’s the thing. The radio waves from each transceiver are emitted in all directions. Take a good look at the map; pay attention to Iceland in the far northwest corner. See the two partially overlapping circles? Iceland has two radar transceivers. Their three dimensional spheres of waves show up as two partially overlapping circles on the map.
Go to Windy.com and zoom way out. You can see islands which have a single transceiver– just one circle.
Here’s the image, again.
This afternoon, let’s zoom in.
The Ukraine does not have a single radar transceiver within its own boarders. The partial coverage– parts of circles that extend over Ukraine’s boarders– are from neighboring countries, Romania, Poland, Russia, Belarus, and others.
As I said, I was astonished when I first saw this. I checked a couple European weather radar sites and it’s not that Windy doesn’t cover the Ukraine. It’s that the Ukraine has no radar coverage.